The book is a biography of Galileo, told partially through letters sent to him from his oldest daughter, Sister Maria Celeste. Although there was a large correspondence between them, only 124 of the letters sent to Galileo survive and none of the ones sent by him are known to exist.
The narrative frequently does not involve his daughter at all, for much of the first part of the book because she had not yet been born and even after her birth, not until she had joined a nunnery and was no longer at home to correspond. Even after, there are long stretches when there is little to no mention of the Maria, so although the book presumes to approach Galileo from that angle, it is not overwhelming.
Much of the early part of the story is dominated by Galileo's novel uses for the telescope and discoveries resulting from it. Namely, the numerous new stars he observed, sunspots, and the moons of Jupiter. From these, Galileo began to support the Copernican, heliocentric model, of the solar system. Even the publication of these first discoveries caused controversies.
I have often seen it argued that Galileo did not truly come under fire from the Church, but rather from fellow scientists* who then pressured the Church to condemn Galileo. This book makes it very clear that this was not the full extent of the case. While other scientists were certainly critical of Galileo and did indeed pressure the Church, there was much vitrol from the Church at the outset as well. One of the first signs Galileo received of possible trouble came from the painter Ludovico Cardi da Cigoli, who warned him that meetings were taking place at the home of the archbishop in Florence of people
in a mad quest for any means by which they could damage you, either with regard to the motion of the earth or otherwise. One of them wished to have a preacher state from the pulpit that you were asserting outlandish things.The letter does not detail who these "ill-disposed men" were, but the fact that they were entertained by the archbishop shows the complicity of the Church from the very start. Whenever other scientists did complain, they did so not on grounds of the merits of the evidence, but relied on arguments from authority because they accepted the Aristotelian, geocentric model as the only one authorized by the Church.
This was largely due to Galileo just being born at the wrong time. After the split of Protestants thanks to Martin Luther, the Church was working hard to explicitly reinforce its position and came down unusually hard on those that would dare question its teachings. The council of Trent in 1546 (the same year Galileo had been born) had declared
no one, relying on his own judgment and distorting the Sacred Scriptures according to his own conceptions, shall dare to interpret them.Another charge against Galileo had asked him to explain how the Earth could move when scripture clearly stated in the book of Joshua that God had stopped the Sun which required that the Sun be the object which was moving. Additionally, Psalms stated
O Lord my God, Thou art great indeed ... Thou fixed the Earth upon its foundation, not to be moved forever.Galileo responded to these by saying that, although scripture could not err, the interpretations of it could. He could then accuse his critics of misinterpreting scripture, but so too, could they accuse him.
By 1614, Galileo was being denounced from the pulpit in Florence. When in 1618 three comets appeared, challenging the immutability of the heavens, Galileo published a series of thoughts on these and was challenged, not by a fellow scientist, but by Father Grassi.
Although there were many challenges to Galileo, none of these were especially escalated. A friend warned him from delving too much deeper into supporting the heliocentric universe and Galileo backed away turning to other topics for a time. However, when his friend Maffeo Cardinal Barberini became Pope Urban VIII in 1623, Galileo felt the time was right to attempt to support his favored model. In 1624 he traveled to Rome to seek permission to write his book supporting heliocentrism and was warned that an outright support was forbidden, but treating it as a hypothetical model, for use in calculations and the like, would be permissible.
Galileo rushed to publish this work, entitled Dialogue on the Two Chief World Systems: Ptolemaic and Copernican. When it neared completion, Galileo had to submit it for censorship since another Church doctrine required that all publications be approved by Church appointed officials. Galileo went through the proper channels and it was approved and eventually made its first print run in 1632.
When it reached Rome, in 1633, Galileo was almost immediately summoned before the inquisition by a group of advisers to the Pope. It was argued that his earlier warning by a friend had been an explicit prohibition to write on, or even discuss Copernican models. Galileo produced a letter showing that it had never been worded so strongly, but the inquisition then argued that Galileo had argued too successfully for the Copernican model. For this, they forced him to repent and ultimately put him under house arrest. Again, this may have been due to Galileo being alive at precisely the wrong time. Urban came down hard on Galileo, perhaps due to, in part, his failure to end the Thirty-Years War and a need to make an example of his decisiveness. Additionally, Urban became paranoid of attacks on him and very well could have interpreted Galileo's works as mocking him.
Through the entire ordeal, his correspondence with his daughter lifted his spirits and while he was stuck in Rome, she managed his affairs from the convent. Although the letters do not add anything to the actual story, they flesh out Galileo as a character and showed how much he cared for his family and his work. She would eventually die before him.
The book also does a wonderful job of showing how Galileo was a true skeptic. He had remarked on "how the prophecies of astrologers could most clearly be seen after their fulfillment." He also challenged his opponents saying they would be prone to error,
when they would base themselves always on a literal meaning of the words [in the Bible]. For in this wise not only many contradictions would be apparently, but even grave heresies and blasphemies wince then it would be necessary to give God hands and feet and eyes, and human and bodily emotions such as anger, regret, hatred, and sometimes forgetfulness of things past, and ignorance of the future.Obviously, Galileo was no literalist.
Galileo noted the vague and intentionally distracting terminology used by his detractors saying, they were commonly
employed by some philosophers as a cloak for the correct reply, which would be: I do not know.Galileo could teach the ID/Creationists of today a thing or two.
That reply, is as much more tolerable than the other as candid honesty is more beautiful than deceitful duplicity.
Ultimately after many years under house arrest, Galileo perished and due to the continued wrath of the Church, he was denied the burial he had requested. However, a succession of friends vowed to move his tomb. Finally, in 1737, permission was granted to give Galileo the interment he deserved. A sculpture was designed to show him presenting a telescope to the muses of Astronomy, Geometry, and Philosophy although the last was removed, likely due to his challenges to religious philosophy.
However, the author notes that although only two females are noticeable, there is, in fact, a third. When Galileo's tomb was opened to move his remains, a second coffin was discovered in his tomb. Only one of the skeletons could have belong to Galileo. The second was that of a younger woman; Galileo's Daughter, who remains by his side.
* - Notice how the Creationist site just says "Many historians" without bothering to even cite them? Yeah. I'm wondering who these "historians" are too and whether they any better than Creation "scientists".